Coordinated IMS and DB2 disaster recovery (separate SLBs with log apply, one-time)
The coordinated IMS and DB2 DR (separate SLBs with log apply) demonstration has a few one-time setup steps for the IMS Recovery Expert and DB2 Recovery Expert products, as shown in Figure 20. The following steps are performed:
- Register IMS and DB2 systems
- Analyze the IMS and DB2 configuration
- Define the system-backup profile for IMS and DB2
- Define the DR profile for IMS and DB2
The steps to register the IMS and DB2 systems are done in both IMS Recovery Expert and DB2 Recovery Expert.
Figure 20. IMS and DB2 one-time setup (primary site activity)
With this coordinated IMS and DB2 DR solution, the SLBs are created and treated independently. In this respect, it is necessary to create separate system backup and DR profiles for IMS and DB2. The IMS Recovery Expert product creates the profiles for IMS, and the DB2 Recovery Expert product creates the profiles for DB2.
The first step for DB2 is to create the system backup profile, which is done with option 1 from the main ISPF menu. In this step, the user specifies the backup technology to be used (FlashCopy, for example) and whether target volumes should be automatically mapped from a pool of volumes or manually specified by the user. This is shown in Figure 21.
Figure 21. DB2 system backup profile (primary site activity)
Defining the system backup profile also includes identifying the target pool and the offload options, including whether the volumes are to be copied to tape, compressed, or encrypted. The JCL to validate and complete this setup is built and submitted as shown in Figure 22. In our demonstration, this JCL job is called DB2SETUP.
Figure 22. DB2 system backup profile job (primary site activity)
After the system profile is created, the JCL to create the SLB used in the runtime environment is built as shown in Figure 23. The JCL built will also offload the SLB using the information specified in the backup profile, and it will also back up the Recovery Expert repository after the SLB has been created and offloaded.
Figure 23. DB2 job to create the DB2 SLB (primary site activity)
The next step is to create the DR profile. In this case, we are creating a DR profile that will be coordinated between IMS and DB2, as shown in Figure 24.
Figure 24. DB2 DR profile (primary site activity)
DB2 Recovery Expert is notified that this is a coordinated IMS and DB2 DR solution by listing the IMS SSID in the external subsystem field, as shown in Figure 25.
Figure 25. IMS SSID in external subsystem field in DB2 DR profile (primary site activity)
The final DB2 one-time setup step is to build the job that is run after each SLB is created for DB2 and after each DB2 log data set is archived. In our demonstration, the job we generate is called DRECOVER. When executed at the production system, this job will collect information about the archived log and SLB so it can be coordinated with an IMS log at the remote site to provide a specific PITR that is consistent between IMS and DB2. When executed, the DRECOVER job will also generate the jobs to restore and recover the DB2 environment at the remote site into a PDS. The recovery jobs generated will have a job name of DREMOTE and are built each time the DRECOVER job is executed.
The onetime steps for IMS Recovery Expert are almost identical to the DB2 Recovery Expert steps. However, when the DR profile is created, the DB2 SSID is put into the external subsystem field as shown in Figure 26.
Figure 26. DB2 SSID in external subsystem field in IMS DR profile (primary site activity)